The Olmsted County Study of Urinary Symptoms and Health Status among Men is a prospective cohort study of urologic aging in a random sample of over 2,000 community-dwelling men. This study has made a number of significant contributions to our understanding of the natural history of signs and symptoms related to benign prostatic hyperplasia (BPH) that are free from the biases present in clinical series of patients. These findings, however, are limited to an initial ten years of follow-up that was funded by Merck Research Labs. Since BPH is a chronic, progressive disease and complications are manifest over extended periods, the continued follow-up of this cohort is necessary to accrue sufficient events to provide long-term risk information. These data are not presently available but are necessary to make informed clinical decisions. Furthermore, extending follow-up will increase the precision of estimates of change in surrogate measures of BPH, providing better insight into what would be expected in community-dwelling men in the absence of a clinical trial setting. The continued follow-up also will provide a better understanding of how serum PSA levels change over time. The specific aims for this application are designed to expand upon our previous findings with an additional four years of follow-up using our well-established protocols. We will determine the 14-year progression of clinical (symptoms), physiologic (peak urinary flow rates) and anatomic (prostate volume) surrogate measures of BPH (Aim 1). We will examine how these vary together over time (Aim 2) and gather information on long-term risk of complications and treatment and relate this to the surrogate measures of BPH (Aim 3). We will also assess the longitudinal changes in serum PSA levels (Aim 4) in order to increase our understanding of the relationship between increases in PSA levels and prostate growth in the absence of cancer. Thus, with the completion of these aims, we will have provided much-needed insight into the role of surrogate measures of BPH in understanding the natural history of this condition in the community at large. This information will prove useful in the design of future clinical trials and epidemiologic studies. Furthermore, we will have provided information that is necessary for informed clinical decision making for treatment of BPH.